Non Patent Literature 1 discloses a picture presentation system using a large semi-transparent mirror film (which is hereinafter sometimes referred to simply as “semi-transparent mirror”). In this system, a floor screen and a semi-transparent mirror are placed in front of a user. The floor screen is placed horizontally on a floor. The semi-transparent mirror is placed in front of a user above the floor screen, and the level of illumination is generally set lower on the backside of the semi-transparent mirror than in the place where the user is. The semi-transparent mirror is tilted at an angle of 45 degrees with respect to the floor screen so that the distance from the floor screen increases as the semi-transparent mirror becomes closer to the user.
In the above configuration, when a picture is projected from a projector onto the floor screen, the picture projected on the floor screen is incident on the semi-transparent mirror, reflected at the angle of reflection which is equal to the angle of incidence, and presented as a virtual image to a user. Because the semi-transparent mirror is tilted at an angle of 45 degrees as described above, it appears to a user that the virtual image of the picture is floating in a front space located on the opposite side from the user across the semi-transparent mirror. In this manner, by creating a virtual image in the space in front of a user (which is hereinafter sometimes referred to as “front space”), it is possible to present the user with a picture that looks as if an object shown in the virtual image was present in front of the user.